tnull
May 30, 2025, 2:19pm
14
Crypt-iQ:
I’m syncing a bitcoind node on my macbook and I can see in Wireshark that it is both fragmenting and reassembling packets greater than 1500 bytes (specifically headers messages). You can run ifconfig or similar on your machine and it will tell you MTU. Packets larger than 1500 bytes can be transmitted, but I believe this requires every router to handle this. I believe the 1500 byte limitation is a legacy thing and may vary with OS but seems to be pretty consistent from what I’ve seen. Hope I’m not link spamming too much but this post gives some history into the 1500 byte limitation (How 1500 bytes became the MTU of the internet ).
Might be worth noting that the actual payload size that can be transmitted without fragmentation is more like 1400 bytes to 1460 bytes (1500 B - 20B (IPv4 header) or 40B (IPv6 header) - 20 to 60 B (TCP header)).
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